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Tuesday, March 27, 2012

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Oph (TOCP Designation: PNV J17260708-2551454) we performed some follow-up of this object remotely through the 0.10-m f/5 reflector + CCD from MPC code H06 (Mayhill station, NM) of iTelescope network.

On our images taken on 2012, March 27.5 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 10.9 at coordinates:

R.A. = 17 26 07.02, Decl.= -25 51 42.1

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our confirmation image:

While below you can see an animation showing a comparison
between our confirmation image and the archive POSS2/UKSTU plate (R
Filter - 1997). Click on the thumbnail for a bigger version:

UPDATE - MARCH 29, 2012

According to Cbet 3072 issued on March 28, observers at Koyama Astronomical Observatory (KAO) and at Okayama University of Science (OUS) have obtained a spectra of this variable star. An H-alpha emission line can be seen in the spectrum. H_beta, Fe II, and O I 777.4-nm are also visible. These features suggest that the object is an "Fe II-type" classical nova. This nova, designated NOVA OPHIUCHI 2012, has been discovered by Hideo Nishimura (Miyawaki, Kakegawa, Shizuoka-ken) on three 13-s frames (limiting mag 13.5) taken on Mar. 25.789 UT with a Canon 200-mm f/3.2 lens and a Canon EOS 5D Digital Camera mounted on a Takahashi EM100 equatorial telescope at Gomyo, Kakegawa, Japan.

Monday, March 26, 2012

CBET 3069 and M.P.E.C. 2012-F87, issued on 2012, March 25, announced the discovery of a periodic comet by A. R. Gibbs on Mar. 22.8, through the Mount Lemmon 1.5-m reflector. On his images, Gibbs, found a stellar coma and a long, narrow tail about 7'.4 long in p.a. 292.5 deg. The new object has been designated P/2012 F5 (GIBBS) by the Minor Planet Center.

We tried its follow up at first on 2012, March 23.8, when this object was still listed in the NEO-CP webpage as "TF85899". We operated from the Malina River Observatory (Povoletto, Italy) through a 0.3-m, f/4.7 reflector + CCD, under a hazy sky. On our stackings we found a faint and narrow, streak, about 2-arcmin long, oriented toward PA 295 deg.

This feature was very close to the expected position of "TF85899" however, due to its faintness (R about 19.2) and curious shape, we suspected it migth be a noise, rather than a real object, so we decided to go for a second night of follow-up, just to make sure. On 2012, Mar. 25.8, we repeated the observations of this object with the same set-up, and found again an odd aspect: kind of elongated and narrow tail, at least 30" long, toward PA300 (in these mages we suspected that the tail might be longer than this, however our observations were hampered by a bright, nearby field star). The central condensation was very difficult to locate, hampering its precise astrometric measurement.

Meanwhile other observers reported about its curious shape in a the [Comets-ml] forum, so we had an indipendent confirmation that what we observed on Mar. 23.8 was actually a real (albeit odd) cometary object, and not an artefact.

Our confirmation image of March 23 (click on it for a bigger version):

According to the preliminary orbital elements issued by the Minor Planet Center, P/2012 F5 has an orbital period of 5.32 years, an inclination on the ecliptic of 13.5 deg, semi-major axis of 3 AU and en eccentricity about 0.4. Its perihelion was reached in September 2010.

Saturday, March 24, 2012

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Cen (TOCP Designation: PNV J13410800-5815470) we performed some follow-up of this object remotely through the 2.0-m f/10.0 Ritchey-Chretien + CCD of "Faulkes Telescope South" (MPC Code - E10).

On our images taken on March 24.5, 2012 we can confirm the presence of an optical counterpart with filtered R-Bessel CCD magnitude 9.3 (USNO-B1.0 Catalogue reference stars) at coordinates:

R.A. = 13 41 09.36, Decl.= -58 15 16.9

(equinox 2000.0; USNO-B1.0 catalogue reference stars).

Our confirmation image (click on it for a bigger version):

While below you can see an animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1994). Click on the thumbnail for a bigger version:

Thursday, March 22, 2012

Cbet Circular No. 3065, issued on 2012, March 22, announces the recovery of comet P/2005 JY126 = P/2012 F4 (CATALINA) by our team; this comet was discovered on 2005, June 7.32 by Catalina Sky Survey and it was last observed on 2007, January 13.

On 2012, March 21.6 we started an observing session to recover the periodic comet P/2005 JY126. We found an object of magnitude ~19.6 located 8.5 arcsec west of the nominal position. Stacking of three R-filtered exposures, 120-sec each, obtained remotely, from the Siding Spring Faulkes Telescope South through a 2.0-m f/10.0 Ritchey-Chretien + CCD, under good seeing conditions,shows that this object appears slightly "soft" compared to the nearby field stars of similar brightness.

On 2012, March 22.4 we have been able to obtain a second night of observations by stacking of 29 R-filtered exposures, 120-sec each, obtained remotely, from the iTelescope network (near Mayhill, NM) through a 0.25-m f/3.4 reflector + CCD.

Below you can find our recovery image of 2012, March 21.6. The red square shows the nominal position, while the circle shows where we actually found the comet.

Comets & Asteroids news

Welcome to our Astronomy blog, devoted in particular to Comets & Asteroids and related topics. This blog is maintained by Italian amateur astronomer Ernesto Guido, particularly active in the study of the small bodies of the Solar System.